1. Field of the Invention
The present invention relates to cargo handling systems. In particular, the present invention relates to cargo handling systems for unloading cargo from a cargo container such as a tractor trailer or a large truck having a cargo container permanently connected thereto.
2. Description of the Related Art
Tractor-trailer rigs are well known in the art. Such rigs are sometimes referred to as "Eighteen Wheelers". The tractor is used to pull the trailer, and the trailer has a cargo carrying container built thereon. The tractor may be quickly disconnected from the trailer.
Other conventional trucks have the engine and the cargo carrying container connected permanently together. Such cargo carrying trucks are usually smaller than tractor-trailer rigs.
The unloading of such a cargo carrying container such as a trailer of a tractor trailer rig typically takes approximately 90 minutes. To unload the trailer or other cargo carrying container, commonly a conventional fork lift is driven onto the trailer and picks up the individual pieces of cargo in the trailer and transports them to the outside of the trailer. Commonly, the individual pieces of cargo are each connected to a pallet to enable the forks of the fork lift to be inserted under the pallet and lift the cargo up to remove the cargo from the trailer.
The truck driver who may be unloading the trailer must rely upon fork lift and the fork lift operator to unload the trailer unless the trailer contains smaller cargo which may be removed by the truck driver by hand or hand-truck.
Cargo handling systems are known in the art. Exemplary of the cargo handling systems of the prior art are those disclosed in the following U.S. Pat. Nos.: 3,688,926; 3,905,494; 3,998,343; 4,111,318; 4,431,360 and 5,054,987.